The hearing comes days after a leaked Justice Department document showed the legal rationale for the killing of an American citizen who had joined Al Qaeda in the Arabian Peninsula.

Brennan, who acted as the President’s top White House counterterrorism adviser in his previous role, faced sharp questions on topics such as drone attacks to his role in the Bush administration’s detention and interrogation program.

"The president believes that John Brennan is uniquely qualified as a 25-year veteran of intelligence work, a 25-year veteran of the CIA, to lead that agency," Carney said. "Mr. Brennan brings, I think, not only a vast amount of experience, but a significant perspective on the battles that we wage in this effort and the right way to conduct them."